The Nigerian air force has killed scores of gunmen, known locally as "bandits", who were members of criminal gangs operating in Zamfara state, the military has said.

The air force said in a statement on Monday that it carried out a raid in Makakkari forest, north-west Nigeria, which was the hideout of the gunmen who were believed to be behind some high-profile kidnappings in the area.

It said it conducted the operation after surveillance detected more than 400 gang members preparing to attack a village.

Over the past two weeks, armed gangs have targeted nearby settlements, killing scores and kidnapping many more. At least 13 security personnel have also been killed.

The aerial strikes, in coordination with attacks on the ground, led to the deaths of "several notorious bandit kingpins and scores of their foot soldiers," air force spokesperson Air Commodore Ehimen Ejodame said.

He added that the ground forces intercepted and killed others trying to flee the forest.

In parts of Nigeria, kidnapping for ransom has become a lucrative business for some.

The bandits, motivated by financial gain, have also increased their cooperation with jihadist groups that have been waging a 16-year armed insurgency in the north-east.

In recent years, the military has launched a number of operations against the gangs, including last month when at least 95 gang members were killed - but the violence has persisted.